The problem says "You have a number of stones with known weights W1, …, Wn. " This is unclear because you can suppose there are more stones than the n weights  (you can imagine two different stones having the same weight). And worst, in the output description, the author's problem uses letter n with two different cases (upper N for the number of stones and lower n for the numbers of weights), this gave me trouble and lets me think the problem was more complicated than it really is.

Please, use the same case for the two letters and, better, be more explicit by starting the statement problem in this way :

You have a number n of stones with known weights W1, …, Wn




Edited by author 05.05.2013 19:55